Tennis swing trainer

ABSTRACT

A tennis swing trainer provides a tennis swing trainer target which outwardly extended on a hand held flexible shaft allows swinging engagement of a tennis racquet.

I. BACKGROUND

A tennis swing trainer provides a tennis swing trainer target whichoutwardly extended on a hand held flexible shaft allows swingingengagement of a tennis racquet.

Sports player swing training devices provide an aid to imprint the feeland reflex of the proper swing in the sports player's mind. The feedbackprovided by a sports player swing training device can be important tocorrectly imprint the proper swing behavior in relation to a particularsports activity. The “feel” of the sports player swing training devicecontributes to the feedback provided to the sports player during use ofthe sports player swing training. With respect to tennis swing training,an important part of the feedback to the tennis player can be the “feel”of the string pattern of the tennis racquet impacting the tennis ball.Altering the “feel” of the impact characteristics between the stringpattern of the tennis racquet and the target object can alter theimprint of the proper swing reflex. Understandably, if the target objectof a tennis swing training device does not generate a “feel” on impactwith the string pattern of the tennis racquet that is sufficientlysimilar to a tennis ball, then the tennis player's swing reflect can beconditioned away from, rather than toward, a swing reflex advantageousto the tennis player during actual tennis play.

Obtaining the proper “feel” in the constructional form and operationalcharacteristics of a tennis swing trainer to correctly condition andimprint a tennis swing reflex may require utilization of a target objector target support elements which impart impact characteristics entirelyunlike or which can be differentiated from the target objects utilizedto make conventional baseball swing training devices, such as describedby U.S. Pat. No. 6,786,841, or conventional volleyball practice devices,such as described by U.S. Pat. No. 5,755,631.

II. SUMMARY OF THE INVENTION

Accordingly, a broad object of the invention can be to provide a tennisswing trainer which provides a tennis swing trainer target whichoutwardly extended on a hand held flexible shaft allows swingingengagement of a tennis racquet.

A second broad object of the invention can be to provide a tennis swingtrainer which provides a constructional form and operationalcharacteristics which provides the proper “feel” to correctly conditionthe tennis swing of a tennis player.

A third broad object of the invention can be to provide methods ofmaking and using a tennis swing trainer which provides the proper “feel”to correctly condition the tennis swing of a tennis player. A particularaspect of this broad object of the invention can be to provide a methodof making and using particular constructional and operational forms of atennis swing trainer target coupled to a flexible shaft which separatelyor in combination provide the proper “feel” to correctly condition thetennis swing of a tennis player.

Naturally, further objects of the invention are disclosed throughoutother areas of the specification, drawings, photographs, and claims.

III. A BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 provides an illustrative example of a particular method of usingan embodiment of the tennis swing trainer.

FIG. 2 provides an illustrative example of a particular method of usingan embodiment of the tennis swing trainer.

FIG. 3 is a side view of a particular embodiment of the tennis swingtrainer in the unflexed condition.

FIG. 4 is a handle end view of a particular embodiment of the tennisswing trainer.

FIG. 5 is a tennis swing trainer target end view of a particularembodiment of the tennis swing trainer.

FIG. 6 is a top view of a particular embodiment of the tennis swingtrainer in the unflexed condition shown by unbroken object lines andbroken lines illustrating the tennis swing trainer in particular flexedconditions.

IV. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A tennis swing trainer (1) provides a tennis swing trainer target (6)which outwardly extended on a hand held flexible shaft (5) allowsswinging engagement of a tennis racquet (12).

Referring primarily to FIG. 1, a particular method of using a tennisswing trainer (1) includes a first person (2) which grips a handle (3)coupled to a first shaft end (4) of a flexible shaft (5) to outwardlyextend a tennis swing trainer target (6) coupled to the second shaft end(7) of the flexible shaft (5) thereby establishing the tennis swingtrainer target (6) at a first tennis swing trainer target location (8).A second person (9) grips a tennis racquet (10) by a tennis racquethandle (11) and swings the tennis racquet head (12) in a swing path (13)to engage the tennis racquet face (14) with the tennis swing trainertarget (6).

Now referring primarily to FIG. 2, impact of the tennis racquet face(14) with the tennis swing trainer target (6) generates an amount oftravel (15) of the tennis swing trainer target (6) consistent with theamount resilient flexure of the flexible shaft (5) and constructionalform of the tennis swing trainer target (6) toward a second tennis swingtrainer target location (16) as the racquet follows through in the swingpath (13) to generate the resiliently flexed condition (23) of theflexible shaft (5)(see also FIG. 6). The resiliently flexed condition(23) generated in the flexible shaft (5) can return the tennis swingtrainer target (6) to the first tennis swing trainer location (8). Byrepeating the above-described steps, the second person (9) can practicea tennis swing by serially engaging the tennis racquet face (14) withthe tennis swing trainer target (6) a plurality of times.

Understandably, the first person (2) can be any person which can gripthe handle (3) of the tennis swing trainer (1) and as to certainembodiments of the tennis swing trainer (1) the person can be replacedby any device which can grip the handle (3) of the tennis swing trainer(1) to establish the tennis swing trainer target (6) at the first tennisswing trainer target location (8). Also, while FIG. 1 shows the tennisswing trainer target (6) established at a particular first tennis swingtarget location (8) to provide forehand tennis swing training, the firsttennis swing target location (8) be established at any location aboutthe first person (2) which may aid in tennis swing training for thesecond person (9). The second person (9) can be any person that can gripthe tennis racquet handle (11) and can swing the tennis racquet head(12) in a swing path (13) to engage the tennis racquet face (14) withthe tennis swing trainer target (6).

Now referring primarily to FIG. 3 and 7, the tennis swing trainer (1)can comprise a flexible shaft (5)(the particular embodiment of thetennis swing trainer shown having a flexible cover (34) partially cutaway to show the flexible shaft (5)) having a first shaft end (4) and asecond shaft end (7). A handle (3) can be coupled to or about a portionof the first shaft end (4) and a tennis swing trainer target (6) can becoupled to or about a portion of the second shaft end (7)(a resilentlyflexible portion (35) of the flexible shaft (5) between the handle (3)and the tennis swing trainer target (6) as shown in FIG. 3). Nowreferring to FIG. 7, the particular embodiment of the tennis swingtrainer (1) shown provides a handle (3) which couples about a length ofthe flexible shaft (17) proximate to the first shaft end (4). The lengthof the flexible shaft (17) about which the first handle part (15)couples can vary depending on the type of engagement between thesurfaces of the handle (3) and the length of the flexible shaft (17). Asto those particular embodiments of the tennis trainer (1) in which thelength of the flexible shaft (17) inserts into a mold to further receivean amount of polymer from which the handle (3) forms, the length of theflexible shaft (17) can be between about six inches and about fourteeninches moldably coupled to handle (3). However, it is not intended thatthe manner by which the handle (3) couples to the flexible shaft (5) belimited to a coupling generated between a length of the flexible shaft(17) and the polymer from which the handle (3) forms in a mold. Rather,a numerous and wide variety of handle (3) materials (such as plastic,wood, metal, or the like) can be configured to couple, interfit, mate,or otherwise engage the first shaft end (4) of the flexible shaftthrough frictional engagement, friction welding, mated spiral threads,post and socket with engagement fixed by mechanical fasteners, or thelike.

The external surface of the handle (3) can be configured in anyconstructional form which allows the first person (2) to grip the handle(3) and outwardly extend the tennis swing trainer (1) asabove-described. Certain embodiments of the handle (3) can furthercomprise a a handle grip (18) and can further comprise a handle butt(19) which function to engage the grip of the first person's hand (20)to act in opposition to travel of the tennis swing trainer away from thefirst person (2) during use. An annular ring (21)(or otherconstructional form) can be provided to attach a leash (22) whichengaged to the first person (2) can function to limit travel of thetennis swing trainer (1) in relation to the location of the first person(2).

The particular constructional form and operational characteristics ofthe flexible shaft (5) or the tennis swing trainer target (6),independently or in combination, are important in generating the properfeel upon impact of the tennis racquet face (14) with the tennis swingtrainer target (6). For example, the feel of sensorially perceivablecharacteristics generated by impact of a tennis racquet face (14) with atennis ball are entirely unlike the feel of sensorial perceivablecharacteristics generated by impact of a baseball bat with a baseball.Because tennis swing training conditions tennis swing behavior based onperceived impact characteristics between the tennis racquet face (14)and the swingingly engaged tennis swing trainer target (6), altering theperceived impact characteristics between the tennis racquet face (14)and the tennis swing trainer target (6) can alter tennis swing behavior.Importantly, if the tennis swing trainer target (6) does not generate a“feel” that is sufficiently similar to a tennis ball on impact with thetennis racquet face (14), then tennis swing behavior can be conditionedaway from, rather than toward, a swing behavior advantageous to thesecond person (9) during actual tennis play. Obtaining the proper “feel”in the constructional form and operational characteristics of the tennisswing trainer (1) to correctly condition the behavior of a tennis swingrequires utilization of a flexible shaft (5) and a tennis swing trainertarget (6), which individually or in combination, provide aconstructional form or operational characteristics entirely unlike orwhich are differentiated from those constructional forms or operationalcharacteristics of conventional baseball swing trainer devices, such asdescribed by U.S. Pat. No. 6,786,841, or conventional volleyballpractice devices, such as described by U.S. Pat. No. 5,755,631.

Now referring to FIGS. 3 and 6, embodiments of the tennis swing trainer(1) having the proper “feel” provide a flexible shaft (5) having aresiliently flexible portion (35) with a length of between about 28inches and about 37 inches (the resiliently flexible portion (35) notincluding any additional length of the flexible shaft (5) surrounded byor engaged by the handle (3) or the tennis swing trainer target (6)).The resiliently flexible portion (35) of the flexible shaft (5) can beconfigured to provide a particular amount of resilient flexure (23) fromthe longitudinal axis (24) of the flexible shaft (5) in the unflexedcondition (25) which allows the tennis swing trainer target (6) totravel a distance (28) of between about two inches and about threeinches (the measure can be taken at the center (36) of the tennis swingtrainer target (6) as shown in FIG. 6) under a load (27) of betweenabout 50 grams (g) and about 80 g (such load attributable in whole or inpart to the tennis swing trainer target (6)). Particular embodiments ofthe tennis swing trainer target (6) having a weight of between about 50g and about 80 g. Although certain embodiments of the tennis swingtrainer target (6) may have greater or lesser weight.

As to the particular embodiment of the tennis swing trainer (1) shown byFIGS. 3 and 7, the flexible shaft (5) can have a substantiallycontinuous diameter between the first shaft end (4) and the second shaftend (7) of between about one-sixteenth inch and about three eighths inchwith a preferred embodiment having a diameter of about one-quarter inch.The flexible shaft can be configured from a variety of materials whichprovide the resilient flexure above-described with a preferredembodiment produced from E-glass reinforcements with a thermoset vinylester resin matrix (“E-glass rod”). A variety of configurations ofE-glass rod suitable for use in the invention can be obtained fromvarious commercial sources such as Glasforms, Inc. of San Diego Calif.

Again referring to FIGS. 3, 6 and 7, the tennis swing trainer (1) canfurther provide a tennis swing trainer target (6) having first targetportion (29) which can be generally spherical with a diameter (36) ofbetween about two and one-half inches and about four inches (althoughcertain embodiments may be of lesser or greater diameter). The tennisswing trainer target (6) can further comprise a second target portion(30) or neck portion coupled to the first target portion (29) whichextends from the first target portion (29) a distance about the secondshaft end (7) of between about two inches to about four inches. Thesecond target portion (30) can have a diameter of between about one inchand about one and one quarter inches. As shown by FIGS. 3 and 7, thesecond target portion (30) can be configured to taper from a greaterdiameter end (31) coupled to the first target portion (29) to a lesserdiameter end (32) terminating at a distance from the first targetportion (29) toward the first end of the flexible shaft (4).

To generate the proper “feel” upon impact of the racquet face (14) withthe tennis swing trainer target (6), the tennis swing trainer target (6)can produced as a polymer foam (33) generated utilizing a reactionmixture including an isocyanate (which without limitation can be in theform of an isothiocyante or MDI prepolymer), a polyol (which can furtherinclude a diluent), a chain extender, a catalyst, and a blowing agentwhich can be introduced into a mold into which a portion of the secondshaft end (7) has been inserted.

While the particular embodiment of the tennis swing trainer (1) shown inFIG. 7, incorporates an amount of methylene diphenyl diisocyanate as aMDI prepolymer in the range of about 5 percent (%) to about 20% (herein% refers to parts per hundred parts of the reaction mixture by weight)or an amount of 4,4′ methylene diphenyl diisocyanate as a MDI prepolymerin the range of about 5% to about 20% (or both in various combinationsin the range of 5% to about 20%) into the reaction mixture, a numerousand wide variety of isocyanates (or isothiocyantes) or mixtures thereofcan be utilized such as: 1,6-hexamethylene diisocyanate, 1,4-butylenediisocyanate, furfurylidene diisocyanate, 2,4-toluene diisocyanate,2.6-toluene diisocyanate, 2,4′-diphenylmethane diisocyanate,4,4′-diphenylmethane diisocyanate, 4,4′-diphenylpropane diisocyanate,4,4′-diphenyl-3,3′-dimethyl methane diisocyanate, 1,5-naphthalenediisocyanate, 1-methyl-2,4-diisocyanate-5-chlorobenzene,2,4-diisocyanato-s-triazine, 1-methyl-2,4-diisocyanato cyclohexane,p-phenylene diisocyanate, m-phenylene diisocyanate, 1,4-naphthalenediisocyanate, dianisidine diisocyanate, bitolylene diisocyanate,1,4-xylylene diisocyanate, 1,3-xylylene diisocyanate,bis-(4-isocyanatophenyl)methane, bis(3-methyl-4-isocyanatophenyl)methane, polymethylene polyphenyl polyisocyanates, or the like.

The tennis swing trainer (1) shown by FIG. 7, can further incorporate anamount of hydroyxl-terminated polyether polyol having a molecular weightof at least 1,500 in the range of about 75% to about 95% (which may havethe viscosity diluted with an amount of propylene carbonate in the rangeof about 1% to about 5%) into the reaction mixture; however, this is notintended to be limiting with respect to the numerous and wide varietiesof polyols that can be included in the reaction mixture which in thealternative can include a hydroxyl-terminated backbone of a memberselected from the group comprising a polyether, a polyester, apolycarbonate, a polydiene and a polycaprolactone, a hydroyl-terminatedpolyhydrocarbon, a hydroxyl-terminated polyformal, a fatty acidtriglycerides, a hydroxyl-terminated polyesters, ahydroxymethyl-terminated polyesters, a hydroxymethyl-terminatedperfluoromethylenes, a polyalkyleneether glycols, apolyalkylenearyleneether glycols, a polyalkyleneether triols, a adipicacid-ethylene glycol polyester, a poly(butylene glycol), apoly(propylene glycol) and a hydroxyl-terminated polybutadiene,separately or in various combinations or permutations.

The tennis swing trainer (1) shown by FIG. 7, can further incorporate anamount of ethylene glycol in a range of about 2% to about 12%, orincorporate an amount of ethylene glycol in a range of about 1% to about5% and an amount of 1,4-butanediol in a range of about 5% to about 10%as a chain extender in the reaction mixture.

The tennis swing trainer (1) shown by FIG. 7, can further incorporate anamount of gel DABCO 33 LV in the range of about 0.1% to about 3% as acatalyst in the reaction mixture; however, this is not intended to belimiting with respect to the numerous and wide varieties of catalyststhat can be included in the reaction mixture and can in the alternativeinclude a DABCO BLV catalyst, a DABCO BL-11 catalyst, a DABCO 2021catalyst, or the like, separately or in various combinations orpermutations.

Similarly, while the tennis swing trainer (1) shown by FIG. 7, canfurther incorporate a hydrofluorocarbon as a blowing agent (alsoreferred to as foaming agents) such as HFC-245fa in the reaction mixturein the range of about 2% to about 12%; this is not intended to belimiting with respect to the numerous and wide varieties of blowingagents which can be included in the reaction mixture such as HFC-134a,HFC-365mfc, HFC141b, cyclopentane, or the like.

Importantly, the amounts of isothiocyanate, the polyol (along with anydiluent), the chain extender, the catalyst, and the blowing agentincluded in the reaction mixture can be adjusted to generate a curedpolymer foam tennis swing trainer target (6) configured asabove-described having the proper “feel” upon impact of the racquet face(14).

Particular embodiments of the tennis swing trainer target (6) having theproper “feel” can have a range of Durometer hardness of between about40A to about 90D, and more preferably a range of Durometer hardness ofbetween about 50A and about 50D. As to the particular embodiment of thetennis swing trainer (1) shown in FIG. 7, and above-described, thedesired “feel” can be generated utilizing a tennis swing trainer target(6) having a first target portion (29) with a diameter of between abouttwo and one-half inches and four inches and Durometer hardness of about40A.

Additionally embodiments of the tennis swing trainer target (6) havingthe proper “feel” can further provide a polymer foam (33) from aproperly adjusted reaction mixture having a density of between about 0.1grams per cubic centimeter and about 0.5 grams per cubic centimeter andmore preferably a density of between about 0.15 grams per cubiccentimeter and about 0.2 grams per cubic centimeter. As to theembodiment of the tennis swing trainer (1) shown in FIG. 7, the tennisswing trainer target (6) having a diameter of between about two andone-half inches to about four inches having a Durometer hardness ofabout 40A, can have a density of about 0.17 grams per cubic centimeterproviding a suitable “feel” upon impact of the racquet face (14) withthe tennis swing trainer target (6). It is intended that the term“tennis swing trainer target” at least generically encompass thenumerous and varied polymer foam objects of generally sphericalconfiguration having a diameter of between two and one-half inches andabout four inches which can be coupled to the second shaft end (7) ofthe flexible shaft (5) having a Durometer hardness within the range of40A to 90D and a density within the range of about 0.1 grams per cubiccentimeter and about 0.5 grams per cubic centimeter, or such narrowerpreferred ranges of one or more parameters as above-described.

Now referring to FIGS. 3 and 7, the tennis trainer (1) can furtherinclude a flexible sleeve (34) about which a portion of the handle (3)couples and about which a portion of the tennis swing trainer target (6)couples. The flexible sleeve (34) acts to protect the flexible shaft (5)from damage upon impact and can protect the first person (2) or thesecond person (9) or other person from fibers that may separate from theflexible shaft. As to the embodiment of the tennis swing trainer shownin FIG. 3, the flexible shaft (5) can have a diameter of aboutone-quarter inch and the flexible sleeve (34) (which can be produced asa polyvinyl tube) can have an internal diameter of between about onequarter inch and about three eighths inch and an external diameter ofbetween about three eighths inch and about one-half inch.

As can be easily understood from the foregoing, the basic concepts ofthe present invention may be embodied in a variety of ways. Theinvention involves numerous and varied embodiments of a tennis swingtrainer and methods of making and using such tennis swing trainer.

As such, the particular embodiments or elements of the inventiondisclosed by the description or shown in the figures accompanying thisapplication are not intended to be limiting, but rather exemplary of thenumerous and varied embodiments generically encompassed by the inventionor equivalents encompassed with respect to any particular elementthereof. In addition, the specific description of a single embodiment orelement of the invention may not explicitly describe all embodiments orelements possible; many alternatives are implicitly disclosed by thedescription and figures.

It should be understood that each element of an apparatus or each stepof a method may be described by an apparatus term or method term. Suchterms can be substituted where desired to make explicit the implicitlybroad coverage to which this invention is entitled. As but one example,it should be understood that all steps of a method may be disclosed asan action, a means for taking that action, or as an element which causesthat action. Similarly, each element of an apparatus may be disclosed asthe physical element or the action which that physical elementfacilitates. As but one example, the disclosure of an “tennis swingtrainer” should be understood to encompass disclosure of the act of“tennis swing training”—whether explicitly discussed or not—and,conversely, were there effectively disclosure of the act of “tennisswing training”, such a disclosure should be understood to encompassdisclosure of a “tennis swing trainer” and even a “means for tennisswing training.” Such alternative terms for each element or step are tobe understood to be explicitly included in the description.

In addition, as to each term used it should be understood that unlessits utilization in this application is inconsistent with suchinterpretation, common dictionary definitions should be understood toincluded in the description for each term as contained in the RandomHouse Webster's Unabridged Dictionary, second edition, each definitionhereby incorporated by reference.

Thus, the applicant(s) should be understood to claim at least: i) eachof the tennis swing trainers herein disclosed and described, ii) therelated methods disclosed and described, iii) similar, equivalent, andeven implicit variations of each of these devices and methods, iv) thosealternative embodiments which accomplish each of the functions shown,disclosed, or described, v) those alternative designs and methods whichaccomplish each of the functions shown as are implicit to accomplishthat which is disclosed and described, vi) each feature, component, andstep shown as separate and independent inventions, vii) the applicationsenhanced by the various systems or components disclosed, viii) theresulting products produced by such systems or components, ix) methodsand apparatuses substantially as described hereinbefore and withreference to any of the accompanying examples, x) the variouscombinations and permutations of each of the previous elementsdisclosed.

The claims set forth in this specification are hereby incorporated byreference as part of this detailed description of the invention, and theapplicant expressly reserves the right to use all of or a portion ofsuch incorporated content of such claims as additional description tosupport any of or all of the claims or any element or component thereof,and the applicant further expressly reserves the right to move anyportion of or all of the incorporated content of such claims or anyelement or component thereof from the description into the claims orvice-versa as necessary to define the matter for which protection issought by this application or by any subsequent continuation, division,or continuation-in-part application thereof, or to obtain any benefitof, reduction in fees pursuant to, or to comply with the patent laws,rules, or regulations of any country or treaty, and such contentincorporated by reference shall survive during the entire pendency ofthis application including any subsequent continuation, division, orcontinuation-in-part application thereof or any reissue or extensionthereon.

The claims set forth below are intended describe the metes and bounds ofa limited number of the preferred embodiments of the invention and arenot to be construed as the broadest embodiment of the invention or acomplete listing of embodiments of the invention that may be claimed.The applicant does not waive any right to develop further claims basedupon the description set forth above as a part of any continuation,division, or continuation-in-part, or similar application.

1. A tennis swing trainer, comprising: a. a flexible shaft having a first shaft end and a second shaft end; b. a handle coupled to said first shaft end; and c. a tennis swing trainer target coupled to said second shaft end.
 2. A tennis swing trainer as described in claim 1, wherein said flexible shaft has a substantially continuous diameter between said first shaft end and said second shaft end of between about one-sixteenth inch and about three eighths inch.
 3. A tennis swing trainer as described in claim 2, wherein said flexible shaft has a substantially continuous diameter between said first shaft end and said second shaft end of about one quarter inch.
 4. A tennis swing trainer as described in claim 2, wherein said flexible shaft between said first shaft end and said second shaft end has a length of between about thirty six inches and about sixty inches.
 5. A tennis swing trainer as described in claim 4, wherein said flexible shaft between said first shaft end and said second shaft end has a length of between about 28 inches and about 37 inches.
 6. A tennis swing trainer as described in claim 4, wherein said flexible shaft in response to a tennis racquet impact on said tennis swing trainer target resiliently flexes.
 7. A tennis swing trainer as described in claim 6, wherein said flexible shaft has a length of between 28 inches and about 37 inches, and wherein said flexible shaft flexes allows said tennis swing trainer target to travel a distance of between about 2 inches to about 3 inches from the longitudinal axis of said flexible shaft in the unflexed condition under a load of between about 50 grams and about 80 grams.
 8. A tennis swing trainer as described in claim 7, wherein said flexible shaft comprises a material selected from the group consisting of a fiberglass, an E-glass-vinyl ester resin composite, and nylon.
 9. A tennis swing trainer as described in claim 6, wherein said tennis swing trainer target has a substantially spherical first portion comprises having a diameter of between about two and one-half inches and about four inches.
 10. A tennis swing trainer as described in claim 9, wherein said tennis swing trainer target comprises a substantially round tennis swing target having a diameter of about one and one quarter inch.
 11. A tennis swing trainer as described in claim 10, wherein said tennis swing trainer target comprises an amount of polymer foam.
 12. A tennis swing trainer as described in claim 11, wherein said polymer foam is derived from a reaction mixture comprising: a. an isocyanate; b. a polyol; c. a catalyst; and d. a blowing agent.
 13. A tennis swing trainer as described in claim 12, wherein said isocyanate is selected from the group consisting of an MDI prepolymer of methylene dipheyl diisocyanate or MDI prepolymer of 4,4′ methylene diphenyl diisocyanate, or mixture thereof.
 14. A tennis swing trainer as described in claim 13, wherein said MDI prepolymer comprises between about 5% and about 20% of said reaction mixture.
 15. A tennis swing trainer as described in claim 14, wherein said polyol comprises high molecular weight polyether polyol of between about 75% and about 95% of said reaction mixture.
 16. A tennis swing trainer as described in claim 15, wherein said catalyst comprises a DABCO 33 LV catalyst of between about 0.1% and about 3% of said reaction mixture.
 17. A tennis swing trainer as described in claim 16, wherein said blowing agent comprises a hydrofluorocarbon blowing agent of between about 2% and about 12%.
 18. A tennis swing trainer as described in claim 17, further comprising a chain extender, wherein said chain extender comprises an amount of ethylene glycol of about 2% to about 12%.
 19. A tennis swing trainer as described in claim 18, wherein said chain extender comprises an amount of ethylene glycol in a range of about 1% to about 5% and an amount of 1,4-butanediol in a range of about 5% to about 10%
 20. A tennis swing trainer as described in claim 11, wherein said amount of polymer foam has a Durometer hardness of between about 40A and about 90D.
 21. A tennis swing trainer as described in claim 20, wherein said amount of polymer foam has a Durometer hardness of between about 50A and about 50D.
 22. A tennis swing trainer as described in claim 21, wherein said amount of polymer foam has a Durometer hardness of about 40A.
 23. A tennis swing trainer as described in claim 20, wherein said amount of polymer foam has a density of between about 0.1 grams per cubic centimeter and about 0.5 grams per cubic centimeter.
 24. A tennis swing trainer as described in claim 21, wherein said amount of polymer foam has a density of between about 0.15 grams per cubic centimeter and about 0.2 grams per cubic centimeter.
 25. A tennis swing trainer as described in claim 22, wherein said amount of polymer foam has a density of about 0.17 grams per cubic centimeter.
 26. A tennis swing trainer as described in claim 10, wherein said tennis swing trainer target further comprises a neck portion which extends from said tennis swing trainer target a distance about said second shaft end.
 27. A tennis swing trainer as described in claim 26, wherein said neck portion extends from said tennis swing trainer target a distance of between about two inches to about six inches
 28. A tennis swing trainer as described in claim 27, wherein said neck portion has a diameter of between about three quarters inches and about one and one quarter inches.
 29. A tennis swing trainer as described in claim 5, further comprising a flexible sleeve disposed about said flexible shaft.
 30. (canceled) 